Wet etching process is widely used in the manufacturing process of a Thin Film Transistor Liquid Crystal Display (TFT-LCD). With continuously updating of various manufacturing processes of LCD panel, a TFT array substrate has more kinds of metal wires, and from aluminum process to copper process and silver process, wet etching process has an important effect on performance and yield of products. The wet etching device mainly has two etching modes: a dip mode and a spray mode; the procedure of etching pattern in the dip mode may be easily controlled, while the etching rate in the spray mode is faster. In the spray mode, etching solution is sprayed onto a surface of an object to be processed through a spray assembly, and the higher the spraying pressure is, the faster the etching rate is.
FIG. 1 is a structural schematic diagram of an existing spray assembly used in the wet etching device. As shown in FIG. 1, the spray assembly 1 includes a spray pipe 1a and a plurality of nozzles 1b connected to the bottom of the spray pipe 1a, and the plurality of nozzles 1b are arranged at equal intervals and fixedly connected with the spray pipe 1a by means of welding. The etching solution flows in from the spray pipe 1a and then is sprayed onto the surface of the object to be processed from the nozzles 1b. FIG. 2 is an exemplary diagram of the wet etching device having the above mentioned spray assembly. As shown in FIG. 2, the wet etching device includes a spray unit 2 which includes a plurality of spray assemblies 1, in which a plurality of spray pipes 1a are arranged in parallel with each other and at equal intervals, and the nozzles 1b connected to the spray pipes 1a are distributed in array. An object-to-be-processed 3 (e.g., a glass substrate on which a metal thin film layer is deposited) is transferred to below the spray unit 2 from a direction (X direction) perpendicular to or approximately perpendicular to the length of the spray pipe 1a, and the nozzles 1b spray etching solution to the surface of the object-to-be-processed 3 for etching.
In the wet etching device as configured above, the nozzles 1b and the spray pipe 1a are fixedly connected by means of welding, and the spray unit 2 composed thereof is also single and fixed. When a nonuniform etching occurs at local in the etching process, all of the spray assemblies 1 (including the spray pipes 1a and the nozzles 1b) in the device need to be replaced, causing an increase in production cost.